Sydney café hostage-taker had long criminal record

Man Haron Monis, the assailant who held 17 people hostage in a Sydney café on Monday, was an Iranian refugee who faced several charges of sexual assault and was known for sending hate mail to the families of Australian soldiers killed overseas.

Monis, also known as Sheikh Haron, was charged last year with being an accessory to his ex-wife's murder. She was stabbed and set on fire in a Sydney apartment block.

He was also found guilty in 2012 of sending threatening letters to the families of eight Australian soldiers killed in Afghanistan as a protest against Australia’s involvement in the conflict, according to local media reports.

Earlier this year, Monis – who described himself as a “spiritual healer” – was charged with the sexual assault of a Sydney woman in 2002. Additional charges were brought against him in October.

His former lawyer said the café stand-off was "not a concerted terrorism event" but the work of "a damaged-goods individual".

New research supports suggestions that solo, “lone wolf” terrorists are more likely to have mental health problems than either members of the general public or participants in group terrorism.

Spaaij and Mark Hamm of Indiana State University studied 98 lone wolf attackers in the United States. They found that 40 percent had identifiable mental health problems, compared with 1.5 percent of the general population.

Spaaj said mental illness can play a part “in shaping particular belief systems and in constructing the enemy, externalising blame for one’s own failure or grievances onto this all-threatening enemy”.

A second study by Paul Gill and Emily Corner of University College London looked at 119 lone wolf attackers and a similar number of members of violent extremist groups in the United States and Europe. Almost one-third of the lone wolves – nearly 32 percent – had been diagnosed with a mental illness while only 3.4 percent of terrorist group members were categorised as mentally ill.

Mental illness may not be the only thing that drives individuals to commit terrorist acts, but it can be a factor.

Monis’s website featured graphic images of children that the website says were killed by US and Australian airstrikes. It also includes media coverage following Monis’s court appearances as well as statements addressed to the Muslim community and Australian Prime Minister Tony Abbott.

Local media reports put Monis's age at 49 or 50. He was killed during the police raid that ended the siege.